386 ORDER MALACOPTERYGII ABDOMTNALES. 



frontal bone, have the cornea and the iris divided into 

 two portions by transverse bands, so that they have 

 two pupils, and appear double, though there is but 

 one crystalline, one vitrea, and one retina 1 ; of 

 this there is no other example among vertebrated 

 animals. The organs of generation and the bladder 

 of the male have their excretory canal in the anterior 

 edge of the anal fin, which is thick, long, and clothed 

 with scales; its extremity is pierced, and doubtless 

 serves the purposes of coition. The female is vivi- 

 parous, and the young are born in a tolerably ad- 

 vanced stage of organization. 



These fishes have a cylindrical body, clothed with 

 strong scales, five rays to the gills, the head flatted, 

 the muzzle truncated, the mouth cleft transversely 

 at the end, and armed in both jaws with small and 

 crowded teeth ; the intermaxillaries without pedicle, 

 and suspended beneath the nasal bones, which form 

 the anterior edge of the snout ; the pectorals in a 

 great measure scaly, and a small dorsal placed over 

 the tail, and farther back than the anal. Their pha- 

 ryngeal bones are large, and furnished with many 

 small globular teeth ; their air-bladder is very large, 

 and their intestine ample, but without cceca. 



But a single species is known, from the rivers of 

 Guiana, Cobitis anableps, L. ; Anableps tetrophtalmus, 

 Bl. 361. 



1 See Lacep. Mem de l'Tnstitut. torn. ii. p. 372. 



